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The 24V battery thermal management system for commercial vehicles (heavy-duty trucks, buses, construction machinery, etc.) is a closed-loop temperature control system with BMS as the control core. The system relies on various actuators such as electronic water pumps, cooling fans, solenoid valves, and PTC heaters to ensure stable and reliable operation of the battery pack under extreme operating conditions such as severe cold and heat. The driving and regulation of loads such as electronic water pumps, cooling fans, solenoid valves, and PTC heaters are mainly achieved through precise control by intelligent high-side switches, thereby ensuring the safe operation of the power battery.

Introduction to 24V Battery Thermal Management Solutions

The intelligent high-side switches represented by RM77100DD and RM77200DQ from Reactor-micro are precisely compatible with the 24V commercial vehicle battery thermal management system, enabling bidirectional regulation of both cooling and heating for its battery pack.

1) Precise Heating: In severe cold environments (below 0°C), the BMS needs to activate the battery pack heating mode. Large commercial vehicle battery packs typically feature a multi-module zoning design, with each zone equipped with an independent PTC heating film or heating element. The four-channel design of RM77200DQ allows for separate control over the on/off status of four heating zones, enabling precise heating management by zones. Additionally, this chip provides basic protection functions such as over-temperature and over-current shutdown for auxiliary loads like PTC heaters, ensuring the stability and reliability of the commercial vehicle battery thermal management system.

2) Efficient refrigeration: The electronic water pump and cooling fan are the "heart" of the cooling circulation system. The BMS calculates the target speed based on the cell temperature and sends a PWM command to the RM77100DD signal input terminal; the chip precisely converts the logic signal into high-side power output, and achieves stepless speed regulation of the device from low-speed warm-up to full-speed cooling by adjusting the duty cycle. At the same time, the chip supports real-time current monitoring, which facilitates the BMS to identify pump and fan stalling faults, thus achieving closed-loop thermal management.

As the core of the thermal management liquid cooling cycle, the water pump, as an inductive load, faces major challenges during startup and locked-rotor conditions. The RM77100DD boasts a high short-circuit withstand capability of 16A, providing ample current margin for water pump startup and resisting transient current surges to prevent accidental triggering of protection mechanisms. When the water pump experiences locked-rotor conditions leading to excessively high current, the chip can swiftly activate the overcurrent protection or thermal shutdown mechanism, achieving passive load shutdown and ensuring equipment safety. Furthermore, the chip offers advanced diagnostic features such as real-time current detection for critical actuators like water pumps and main valves, accurately transmitting load operation data to the MCU, thereby facilitating more efficient closed-loop regulation in the thermal management system.

In addition to their core cooling and heating control functions, the two intelligent high-side switches, RM77100DD and RM77200DQ, can also be extended to applications such as sensor power distribution and LED auxiliary load driving, further enriching the product's application scenarios and providing a more comprehensive and diversified solution for commercial vehicle 24V battery thermal management systems.

Product selection recommendation

As domestically produced intelligent high-side switches, the Yachengwei RM77100DD and RM77200DQ can achieve PIN-to-PIN replacement of similar products from international first-tier brands. Currently, they have been firstly mass-produced by domestic mainstream commercial vehicle electronic control Tier 1 suppliers and leading power battery manufacturers in the industry. The product delivery and quality control have received unanimous praise from the market.

I. RM77100DD VS RM77200DQ

II. Product Performance Features:

• The standby current is extremely low, approximately 0.1 uA.

• 3.3 V and 5V compatible logic inputs.

• Electrostatic discharge protection (ESD).

• Optimize electromagnetic compatibility.

• Logical grounding independent of load grounding.

• Low-power DMOS leakage current state during shutdown.

• Integrates multiple core protection functions such as Short Circuit Protection (SCP), Over Voltage Protection (OVP), and Over Temperature Protection (OTP).

• It has an open circuit detection function.

For sample requests, product purchases, or technical inquiries, please feel free to call: （86）029-88827769/18009231253. Our team will respond promptly and provide you with efficient and reliable solutions.